JP7262720B2 - circular polarizer - Google Patents

Description

This application relates to circular polarizers.

This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0133585 filed November 2, 2018, and all content disclosed in the documents of the Korean Patent Application is hereby incorporated by reference. included as part of

A so-called circular polarizer, which basically comprises a polarizer and a retardation film, can be used to lower the surface reflection in the Off state of the OLED panel. For example, Patent Document 1 (Japanese Laid-Open Patent Publication No. 8-321381) discloses a method of arranging a circularly polarizing plate on the side of a transparent electrode in an organic light-emitting device. When the retardation film used for the circularly polarizing plate has a reverse dispersion characteristic, it is the most excellent because the reflection color is natural, but the price is very high due to the characteristics of the material.

The present application provides a circularly polarizing plate and an OLED device including the circularly polarizing plate that can improve the reflected color using a retardation film with flat dispersion characteristics.

This application relates to circular polarizers. FIG. 1 exemplarily shows the circular polarizer of the present application. As shown in FIG. 1, the circularly polarizing plate 100 of the present application may include an antireflection film 10, a polarizer 20, a retardation film 30 and an adhesive layer 40 in order. The retardation film may have flat dispersion characteristics. The minimum reflection wavelength of the antireflection film may be 470 nm or less. An in-plane retardation value of the retardation film at a wavelength of 550 nm may be 136.0 nm or more. The circular polarizer may have a transmittance of 30% or less for a wavelength of 430 nm.

In the present application, through such a circularly polarizing plate, it is possible to improve the reflection color feeling even when using a retardation film having a flat dispersion characteristic. The circularly polarizing plate of the present application will be specifically described below.

The reflectance of the antireflection film is about 2.0% or less, 1.9% or less, 1.8% or less, 1.7%, measured with the circularly polarizing plate attached to the OLED panel described later. % or less or 1.6% or less. The above reflectance may mean the luminous reflectance Y (D65).

The reflectance of the antireflection film at a wavelength of 550 nm may be 0.6% to 1.2%. The antireflection film may have a transmittance of 90% or more or 95% or more for light with a wavelength of 380 nm to 780 nm. The haze of the antireflection film may be, for example, 1% or less. Although the lower limit of haze of the antireflection film is not particularly limited, it can be, for example, 0.01% or more.

The antireflection film can satisfy L ^* a ^* b ^* color coordinate criteria a ^* >0, b ^* >0 and a ^* <b ^* determined according to the method defined in CIE 1976. Through the use of such antireflection films, it may be further advantageous to use retardation films with flat dispersion characteristics to improve reflected color.

The antireflective film can have a minimum reflection wavelength of 470 nm or less, 465 nm or less, or 460 nm or less. In the present specification, the minimum reflection wavelength may mean the wavelength at which the reflectance appears lowest in the reflectance spectrum for the wavelength of the anti-reflection film. The minimum reflection wavelength of the antireflection film can be, for example, 390 nm or greater, 395 nm or greater, or 400 nm or greater. The antireflection film may have a minimum reflectance of, for example, 1.0% or less. As used herein, the lowest reflectance may mean the reflectance at the point where the reflectance appears lowest in the reflectance spectrum for wavelength of the anti-reflection film.

Antireflection films can exhibit a U-shaped graph of reflectance versus wavelength. FIG. 2(a) exemplarily shows a U-shaped graph, and FIG. 2(b) exemplarily shows a W-shaped graph. However, FIG. 2 is a drawing for exemplifying the U-shaped graph, and the scope of the present application is not limited to FIG. The antireflection film may have a reflection band exhibiting the lowest reflectance within the wavelength range of 380 nm to 780 nm, for example, one wavelength band having a reflectance of 1% or less (region _R1 in FIG. 2(a)). Such a U-shaped graph is distinguished from a W-shaped graph, which is a region (R ₁ and R ₂ in FIG. 2(b)) having two reflection bands exhibiting the lowest reflectance within the wavelength range of 380 nm to 780 nm. can be a concept Through the use of such antireflection films, it may be further advantageous to use retardation films with flat dispersion characteristics to improve reflected color.

If the optical properties of the antireflection film are within the above range, the material can be appropriately selected. For example, an antireflective film can include a low refractive layer. It is known to adjust the optical properties of the antireflection film within the above ranges. For example, the minimum reflection wavelength of an antireflection film tends to shift to a longer wavelength as the thickness of the low refractive layer increases, and shifts to a shorter wavelength as the thickness of the low refractive layer decreases. For example, the minimum reflectance of an antireflection film tends to decrease as the refractive index of the low refractive material decreases.

The low refractive layer can contain a low refractive material. In one example, the low refractive material can be low refractive inorganic particles. The refractive index of the low refractive inorganic particles at 550 nm wavelength can be, for example, 1.5 or less, 1.45 or less, or 1.40 or less. The lower limit of the refractive index can be, for example, 1.0 or more, 1.1 or more, 1.2 or more, or 1.3 or more.

In one example, the low refractive inorganic particles can be silica-based particles. Examples of silica-based particles include hollow silica, mesoporous silica, and the like. In another example, magnesium fluoride ( _MgF2 ) can be used as the low refractive inorganic particles.

In one example, the low refractive inorganic particles can be nano-sized particles. The average particle size of the low refractive inorganic particles can be in the range, for example, 10 nm to 700 nm, 10 nm to 500 nm, 10 nm to 300 nm, 10 nm to 200 nm or 10 nm to 100 nm.

The thickness of the low refractive layer can be adjusted appropriately in view of the purposes of this application. The thickness of the low refractive layer can be, for example, in the ranges 10 nm to 500 nm, 10 nm to 300 nm, 10 nm to 200 nm, 50 nm to 200 nm or 100 nm to 200 nm. As described above, since the minimum reflection wavelength of the antireflection film can be adjusted according to the thickness of the low refractive layer, the thickness of the low refractive layer is appropriately adjusted within the above range in consideration of the desired minimum reflection wavelength. be able to.

The low refractive layer may further contain a binder resin. The low refractive inorganic particles may be present in a dispersed state within the binder resin.

The low refractive layer may contain 30 to 600 parts by weight of the low refractive inorganic particles for 100 parts by weight of the binder resin. Specifically, the low refractive index inorganic particles may be included in the range of 30 to 500 parts by weight, 30 to 400 parts by weight, 30 to 300 parts by weight, 30 to 200 parts by weight, or 100 to 200 parts by weight with respect to 100 parts by weight of the binder resin. . If the content of the low-refractive inorganic particles is excessively high, the reflectance may be increased, and surface irregularities may be excessively generated, thereby deteriorating surface properties such as scratch resistance and stain resistance.

The binder resin can be, for example, a photopolymerizable compound. Specifically, the photopolymerizable compounds can include monomers or oligomers containing (meth)acrylate groups or vinyl groups. More specifically, the photopolymerizable compound can include monomers or oligomers containing one or more, or two or more, or three or more (meth)acrylate groups or vinyl groups.

Specific examples of monomers or oligomers containing (meth)acrylate groups include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa( meth)acrylate, tripentaerythritol hepta(meth)acrylate, tolylene diisocyanate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, butanediol Dimethacrylate, butyl methacrylate, or mixtures of two or more thereof, or urethane-modified acrylate oligomers, epoxide acrylate oligomers, ether acrylate oligomers, dendritic acrylate oligomers, or mixtures of two or more thereof. At this time, the molecular weight of the oligomer is preferably in the range of 1,000 to 10,000.

Specific examples of monomers or oligomers containing vinyl groups include divinylbenzene, styrene or paramethylstyrene.

Meanwhile, the photopolymerizable compound may further include fluorine-based (meth)acrylate-based monomers or oligomers in addition to the above-described monomers or oligomers. When the fluorine-based (meth)acrylate-based monomer or oligomer is further included, the weight of the fluorine-based (meth)acrylate-based monomer or oligomer relative to the monomer or oligomer including the (meth)acrylate group or vinyl group The ratio can be in the range 0.1% to 10%.

The antireflection film may further include a substrate layer, and the low refractive layer may be formed on one surface of the substrate layer.

The base layer may contain a light-transmissive resin. Accordingly, the substrate layer can be a light-transmissive substrate layer. The substrate layer may have, for example, a transmittance of 90% or greater for light with wavelengths between 380 nm and 780 nm. The substrate layer may have a haze of 1% or less for light with a wavelength of, for example, 380 nm to 780 nm. It would be further advantageous to provide an anti-reflective film in which reflectance can be reduced while maintaining high transmittance through the use of such a substrate layer.

The substrate layer is selected from the group consisting of triacetyl cellulose (TAC) film, cycloolefin polymer film, poly(meth)acrylate film, polycarbonate film, polynorbornene film and polyester film. One or more can be included. The thickness of the base layer may be in the range of 10 μm to 300 μm in consideration of productivity, but is not limited to this.

The low refractive layer can be produced by coating and curing the composition for forming a low refractive layer on the substrate layer. The composition for forming a low refractive layer may contain the low refractive inorganic particles, and may further contain the binder resin. As will be described later, when a hard coating layer is formed on the substrate layer, the low refractive layer can be formed by coating the hard coating layer with the composition for forming a low refractive layer and curing the hard coating layer.

A method of coating the composition for forming a low refractive layer is not particularly limited, and may be performed by known coating methods such as spin coating, bar coating, roll coating, gravure coating, blade coating, and the like.

The method of curing the composition for forming a low refractive layer is not particularly limited, and can be performed, for example, by irradiation with light or application of heat. The photo-curing of the composition for forming a low refractive layer may be performed by irradiating ultraviolet rays or visible rays with a wavelength of 200 nm to 400 nm. Also, the exposure amount during light irradiation may be in the range of 100 mJ/cm ² to 4,000 mJ/cm ² . The exposure time is also not particularly limited, and can be appropriately changed according to the exposure apparatus used, the wavelength of the irradiation light, or the amount of exposure.

The antireflection film may further include a hard coating layer. A hard coating layer may be present between the substrate layer and the low refractive layer. The hard coating layer can improve the hardness of the antireflection film. Through this, the antireflection film can be used as the outermost optical film of the display device, ie, the window film.

The refractive index range of the hard coating layer can be appropriately selected within a range that does not impair the purpose of the present application. The hard coating layer can have a refractive index, for example, 1.5 or less, 1.40 or 1.30 or less, for a wavelength of 550 nm, for example. The lower limit of the refractive index can be, for example, 1.0 or more, 1.1 or more, or 1.2 or more.

As the hard coating layer, commonly known hard coating layers can be used without particular limitation. The hard coating layer can contain, for example, a photocurable resin. The photocurable resin can be a light transmissive resin. The photocurable resin contained in the hard coating layer is a polymer of a photocurable compound capable of undergoing a polymerization reaction when irradiated with light such as ultraviolet rays, and may be commonly used in the art. Specifically, the photocurable resin is a reactive acrylate oligomer group consisting of urethane acrylate oligomer, epoxide acrylate oligomer, polyether acrylate, and polyether acrylate; and dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylenepropyl triacrylate, propoxylated glycerol triacrylate, trimethylpropaneethoxy triacrylate, 1,6-hexanediol diacrylate, propoxylated glycerol triacrylate, tripropylene glycol diacrylate, and It may contain one or more selected from the group of polyfunctional acrylate monomers consisting of ethylene glycol diacrylate.

The hard coating layer may further include organic or inorganic fine particles dispersed in the photocurable resin. Specific examples of the organic or inorganic fine particles contained in the hard coating layer are not limited. For example, the organic or inorganic fine particles are one or more selected from the group consisting of acrylic resins, styrene resins, epoxide resins and nylon resins. or one or more inorganic fine particles selected from the group consisting of silicon oxide, titanium dioxide, indium oxide, tin oxide, zirconium oxide and zinc oxide. The particle size of the organic or inorganic microparticles is not specifically limited, for example, the organic microparticles can have a particle size of 1-10 μm, and the inorganic particles can have a particle size of 1 nm-500 nm or 1 nm-300 nm. The particle size of the organic or inorganic microparticles can be defined by the volume average particle size

The thickness of the hard coating layer can be, for example, in the range of 0.1 μm to 100 μm. The pencil hardness of the antireflection film to which the hard coating layer is applied may be, for example, 2H or higher or 4H or higher. Within this range, it may be advantageous to protect the transparent display element from the outside even when the antireflection film is used as the outermost window film of the display device.

The hard coating layer can be produced, for example, by coating and curing the hard coating layer-forming composition on the substrate layer. The composition for forming a hard coating layer may contain the photocurable resin, and if necessary, may further contain the organic or inorganic fine particles.

A method for curing the composition for forming a hard coating layer is not particularly limited, and may be performed, for example, by irradiation of light or application of heat. The photo-curing of the composition for forming a hard coating layer can be performed by irradiating ultraviolet rays or visible rays with a wavelength of 200 nm to 400 nm. Also, the exposure amount during light irradiation may be in the range of 100 mJ/cm ² to 4,000 mJ/cm ² . The exposure time is also not particularly limited, and can be appropriately changed according to the exposure apparatus used, the wavelength of the irradiation light, or the amount of exposure.

The composition for forming a low refractive layer or the composition for forming a hard coating layer may further contain a solvent. The solvent can be an organic solvent. A hydrocarbon-based, halogenated hydrocarbon-based or ether-based solvent can be used as the organic solvent. Examples of hydrocarbon solvents include pentane, hexane, heptane, cyclohexane, n-decane, n-dodecane, benzene, toluene, xylene and methoxybenzene solvents. Examples of halogenated hydrocarbon solvents include carbon tetrachloride, chloroform, 1,2-dichloroethane, dichloromethane and chlorobenzene solvents. Examples of ether solvents include tetrahydrofuran, thioxane, propylene glycol monomethyl ether acetate solvents and the like.

The composition for forming a low refractive layer or the composition for forming a hard coating layer may further contain optional additives. Such additives include, for example, curing agents and catalysts that assist curing of the curable resin, initiators such as radical initiators and cationic initiators, thixotropic agents, leveling agents, antistatic agents, antifoaming agents, agents, antioxidants, radical-generating substances, inorganic or inorganic pigments or dyes, dispersants, various fillers such as thermally conductive fillers and insulating fillers, functional polymers, light stabilizers, etc., but are limited to these. not to be

As used herein, the term polarizer means a film, sheet or element having a polarizing function. A polarizer is a functional element that can extract light oscillating in one direction from incident light oscillating in various directions.

As used herein, the terms polarizer and polarizer refer to distinct objects. The term polarizer means a film, sheet or element having a polarizing function per se, and the term polarizer means an object including other elements laminated on one or both sides of the polarizer. Examples of the above other elements include a protective film for a polarizer, an antireflection film, a retardation film, an adhesive layer, an adhesive layer, and a surface treatment layer, but are not limited thereto. The circularly polarizing plate of the present application may or may not include a protective film attached to one or both sides of the polarizer. An anti-reflection film and/or a retardation film can act as a protective substrate of the polarizer without a separate protective film attached to one or both sides of the polarizer.

As a polarizer in this application, an absorbing linear polarizer can be used. As such a polarizer, a PVA (poly(vinyl alcohol)) polarizer is known. In principle, known polarizers can be used as polarizers in this application. In one example, a known PVA (poly(vinyl alcohol)) polarizer having the following characteristics can be applied.

The transmittance of the polarizer for 550 nm wavelength can be in the range of 40% to 50%. The transmittance may specifically be in the range of 42%-43% or 43.5%-44.5%. The transmittance may refer to the single transmittance of the polarizer for 550 nm wavelength. The single transmittance of the polarizer can be measured using, for example, a spectrometer (V7100, manufactured by Jasco). For example, with the polarizer sample (not including the upper and lower protective films) placed on the instrument, air is set as the base line, and the axis of the polarizer sample is aligned vertically and horizontally with the axis of the reference polarizer. Single transmittance can be calculated after each transmittance is measured.

Normally, a PVA-based absorbing linear polarizer exhibits the above single transmittance, and such a PVA-based absorbing linear polarizer can be applied in the present application, but as long as it exhibits the above single transmittance The types of polarizers that can be used are not limited to the above.

A PVA-based polarizer generally includes a PVA film or sheet and a dichroic dye or an anisotropic water-absorbing substance such as iodine adsorbed and oriented on the PVA film or sheet.

A PVA film or sheet can be obtained, for example, by gelling polyvinyl acetate. Examples of polyvinyl acetate include homopolymers of vinyl acetate; and copolymers of vinyl acetate and other monomers. Examples of other monomers to be copolymerized with vinyl acetate include one or more of unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfonic acid compounds, and acrylamide compounds having an ammonium group. can be

The degree of gelation of polyvinyl acetate is generally about 85 mol % to about 100 mol % or 98 mol % to 100 mol %. The degree of polymerization of the polyvinyl alcohol of the linear polarizer can generally be from about 1,000 to about 10,000 or from about 1,500 to about 5,000.

A PVA polarizer is manufactured from a PVA film or sheet through a dyeing process and a stretching process. If necessary, the manufacturing process of the polarizer may further include swelling, cross-linking, washing and/or drying processes.

For example, the above dyeing step is a step for adsorbing iodine, which is an anisotropically absorbent material, to the PVA film or sheet, and the PVA film or sheet is immersed in a treatment tank containing iodine and potassium iodide. However, during this process, the single transmittance can be adjusted by adjusting the concentrations of iodine and potassium iodide in the treatment tank.

In the dyeing process, the PVA film or sheet is immersed in a dyeing solution or cross-linking solution containing iodine (I ₂ ), iodides such as KI, and/or boric acid compounds (boric acid or borate). A water-absorbing substance is adsorbed on the PVA film or sheet. Therefore, in the above process, the type or amount of the anisotropic water-absorbing substance adsorbed on the polarizer is determined according to the concentration of the compound in the staining solution, thereby determining the absorptance and transmittance of the polarizer for light of a specific wavelength. can be determined.

For example, the species of iodine compounds that can be present in the staining solution can be I ⁻ , I ₂ , I ₃ ⁻ or I ₅ ⁻ derived from iodide (M ⁺ I ⁻ ) and iodine (I ₂ ). However, among the above compounds, I ⁻ has an absorption wavelength range of about 190 nm to 260 nm and has little effect on color sensation, and I ₂ has an absorption wavelength range of about 400 nm to 500 nm and has a color sensation mainly of red. I ₃ ⁻ has an absorption wavelength range of about 250 nm to 400 nm ^, _and its color is mainly yellow. The curved structure of I ₅ ⁻ has an absorption wavelength range of about 500 nm to 900 nm, and its color is mainly blue.

The retardation film may have flat dispersion characteristics. A flat dispersion characteristic herein may mean a characteristic in which the retardation value is constant as the wavelength increases. In one example, the flat dispersion characteristic may mean that the R(450)/R(550) value of the retardation film is 0.99-1.01. Also, according to the flat dispersion characteristics, the R(650)/R(550) value of the retardation film may be 0.99 to 1.01. In the above, R(λ) may mean the in-plane retardation value for λnm wavelength. A retardation film with a flat dispersion characteristic has the advantage of being available as a commercially available product at a low price compared to a retardation film with an inverse dispersion characteristic. In addition, since the retardation film with flat dispersion characteristics does not require an additional coating process, it is advantageous in process yield.

Herein, the in-plane retardation value can be calculated by Equation 1 below.

[Formula 1]
Rin=d×(nx−ny)

In Equation 1, Rin is an in-plane retardation, nx and ny are the refractive indices of the retardation film in the x-axis direction and the y-axis direction, respectively, and d is the thickness of the retardation film. Such definitions are equally applicable herein unless specified otherwise. In the above, the x-axis direction means the in-plane slow axis direction of the retardation film, the y-axis direction means the in-plane direction (fast axis direction) perpendicular to the x-axis, and the z-axis direction means the above It may refer to the direction normal to the plane formed by the x-axis and the y-axis, eg, the thickness direction of the retardation film. In the present specification, the slow axis may mean an axis parallel to the direction in which the refractive index is highest based on the in-plane direction of the retardation film. Unless otherwise specified when referring to the refractive index herein, the refractive index is for light having a wavelength of about 550 nm.

The in-plane retardation value of the retardation film at a wavelength of 550 nm may be 137.5 nm or more. An in-plane retardation value of the retardation film at a wavelength of 550 nm may be, for example, 143 nm or less. More specifically, the in-plane retardation value of the retardation film at a wavelength of 550 nm may be in the range of 137.5 nm to 141.0 nm. Within such ranges, flat dispersion retardation films may be used to improve reflective visual perception.

A method for adjusting the in-plane retardation value of a retardation film is known. In one example, when the retardation film is a stretched polymer film, the in-plane retardation value can be adjusted by adjusting the material, thickness, and stretching ratio of the polymer film. In another example, when the retardation film is a liquid crystal polymer film, the in-plane retardation value can be adjusted by adjusting the thickness of the liquid crystal layer, the birefringence value of the liquid crystal, and the like.

The slow axis of the retardation film can form an angle of 43° to 47°, 44° to 46°, preferably 45° with the absorption axis of the polarizer. Through this, the reflective visual sensation of the circularly polarizing plate using the flat dispersion retardation film can be improved. In this specification, the angle formed by the A axis with respect to the B axis includes both the angle formed by the A axis in the clockwise direction and the angle formed by the A axis in the counterclockwise direction with respect to the B axis of 0 degrees. could be.

The thickness of the retardation film may be, for example, within the range of 10 μm to 100 μm when it is a stretched polymer film. In another example, the thickness of the retardation film can be, for example, within the range of 0.1 μm to 5 μm when it is a liquid crystal polymerized film.

The retardation film can be a liquid crystal polymerized film or a polymer stretched film. Specifically, as the retardation film, a stretched polymer layer or a liquid crystal layer obtained by stretching a polymer film capable of imparting optical anisotropy by stretching in an appropriate manner can be used. As the liquid crystal layer, a liquid crystal polymer layer or a cured layer of a polymerizable liquid crystal compound can be used.

The liquid crystal polymer film may include a substrate layer and a liquid crystal layer on one side of the substrate layer. For the substrate layer of the liquid crystal polymer film, the above-described content regarding the substrate layer of the antireflection film can be applied in the same manner. Therefore, the substrate layer of the liquid crystal polymer film can also use a light-transmitting substrate. The liquid crystal layer may include a polymerizable liquid crystal compound in a polymerized state. As used herein, the term 'polymerizable liquid crystal compound' may refer to a compound that includes a site capable of exhibiting liquid crystallinity, such as a mesogen skeleton, and one or more polymerizable functional groups. Such polymerizable liquid crystal compounds are variously known under the name of so-called RM (Reactive Mesogen). The polymerizable liquid crystal compound may be contained in a polymerized form in the cured layer, that is, in the polymerized units described above. It can mean the state of forming a skeleton such as a side chain

The polymerizable liquid crystal compound can be a monofunctional or multifunctional polymerizable liquid crystal compound. The monofunctional polymerizable liquid crystal compound may refer to a compound having one polymerizable functional group, and the multifunctional polymerizable liquid crystal compound may refer to a compound including two or more polymerizable functional groups. In one example, the polyfunctional polymerizable liquid crystal compound has 2 to 10 polymerizable functional groups, 2 to 8 groups, 2 to 6 groups, 2 to 5 groups, 2 to 4 groups, 2 to It can contain 3 or 2 or 3.

A state in which a polymerizable liquid crystal composition produced by blending the polymerizable liquid crystal compound as described above with other components such as an initiator, a stabilizer and/or a non-polymerized synthetic liquid crystal compound is oriented on an alignment film It is known to form the above cured layer having birefringence by curing with. The retardation film having flat dispersion characteristics can be manufactured by including a polymerizable liquid crystal compound having flat dispersion characteristics.

Examples of stretched polymer films include polymer materials such as polyolefins such as polyethylene and polypropylene, cyclic olefin polymers (COPs) such as polynorbornene, polyvinyl chloride, polyacrylonitrile, polysulfone, acrylic resins, polycarbonate, and polyethylene. A polymer layer containing a polyester such as terephthalate, a cellulose ester polymer such as polyacrylate, polyvinyl alcohol or TAC (triacetyl cellulose), or a copolymer of two or more monomers among the monomers forming the above polymers. can be used.

A method for obtaining a polymer stretched film is not particularly limited. For example, it can be obtained by forming the polymer material in the form of a film and then stretching the film. The method of forming the film is not particularly limited, and the film can be formed by known methods such as injection molding, sheet molding, blow molding, injection blow molding, inflation molding, extrusion molding, foam molding, and cast molding. , and a secondary processing molding method such as air pressure molding or vacuum molding can also be used. Among them, extrusion molding and cast molding are preferably used. At this time, the unstretched film can be extruded using an extruder equipped with, for example, a T-die, a circular die, or the like. When a molded article is obtained by extrusion molding, a material obtained by melt-kneading various resin components, additives, etc. in advance may be used, or may be molded after melt-kneading during extrusion molding. Also, an unstretched film can be cast-molded by dissolving various resin components using a solvent common to various resin components, such as chloroform and methylene dichloride, followed by solidification by casting and drying.

The polymer stretched film is obtained by uniaxially stretching the above molded film in the mechanical flow direction, mechanical direction (MD; mechanical direction, machine direction or length direction) perpendicular to the direction (TD; transverse direction, transverse direction or width direction). direction), and a biaxially stretched film by stretching by a sequential biaxial stretching method of roll stretching and tenter stretching, a simultaneous biaxial stretching method by tenter stretching, a biaxial stretching method by tubular stretching, etc. may be manufactured.

Controlling the retardation value of a stretched polymer film can generally be accomplished by controlling the stretching conditions of the film. This is because the retardation value depends on the thickness of the film itself due to stretching of the film. In the case of biaxial stretching, the ratio of the draw ratio (MD direction/TD direction) between the mechanical flow direction (MD direction) and the direction perpendicular to the mechanical flow direction (TD direction) should be 0.67 or less or 1.5 or more. 0.55 or less or 1.8 or more is more preferable, and 0.5 or less or 2 or more is most preferable.

The adhesive layer can perform the function of adhering the circularly polarizing plate to the display panel. The adhesive layer may contain an adhesive resin. As the tacky resin, for example, a light-transmitting tacky resin can be used. For example, using an adhesive resin that makes the transmittance of the adhesive layer formed by the adhesive resin to a wavelength of 380 nm to 780 nm about 80% or more, 85% or more, 90% or more, or 95% or more. can be done. The transmittance may mean the percentage of the amount of light transmitted through the adhesive layer relative to the amount of light incident on the adhesive layer. The adhesive resin is, for example, any one or more selected from the group consisting of acrylic resins, silicone resins, ester resins, urethane resins, amide resins, ether resins, fluorine resins, and rubber resins. can include

The thickness of the adhesive layer can be, for example, within the range of 15 μm to 30 μm.

The method of forming the pressure-sensitive adhesive layer on one surface of the retardation film is not particularly limited. In one example, after forming a pressure-sensitive adhesive layer by applying the pressure-sensitive adhesive composition containing the pressure-sensitive adhesive resin to the release film, the pressure-sensitive adhesive layer is transferred to one surface of the retardation film, and the release film is removed. can be accomplished by the step of In another example, the pressure-sensitive adhesive layer can be formed by directly applying the pressure-sensitive adhesive composition on one surface of the retardation film.

A circular polarizer can contain a dye. The dye functions to control the transmittance of the circular polarizer. As used herein, a dye may refer to a substance capable of intensively absorbing and/or transforming light within at least some or all of the visible light region, eg, the 380 nm to 780 nm wavelength range.

A circular polarizer containing a dye may have a transmittance of 30% or less or 28% or less for a wavelength of 430 nm. Since the circularly polarizing plate can contribute to the neutral reflection color by satisfying such a transmittance range, it is possible to improve the reflective visual sensation even when using a retardation film with a flat dispersion characteristic. More specifically, the circular polarizer containing the dye may have a transmittance of 35% or more or 40% or more for wavelengths of 460 nm and 550 nm, respectively.

The lower limit of the transmittance of the dye-containing circular polarizer to a wavelength of 430 nm may be 4% or more. If the transmittance is too low, the color change of white light emitted from the OLED becomes excessively large.

The dye may be appropriately selected within the range that allows the circularly polarizing plate to exhibit the above transmittance characteristics. The dye can be, for example, a dye that absorbs in the blue region. The above dyes can exhibit maximum absorbance in the blue region. Herein, the absorption or absorbance of a dye can be determined from a transmittance spectrum measured for a layer formed by mixing a dye with a light-transmissive resin. In this specification, the light-transmitting resin is a layer having a transmittance of about 80% or more, 85% or more, 90% or more, or 95% or more for a wavelength of 380 nm to 780 nm, measured for a layer formed of the above resin alone. can mean

A dye having absorption properties as described above may be abbreviated herein as a Blue cut dye. The blue region can be, for example, within the 370 nm to 430 nm wavelength range. Therefore, the circularly polarizing plate containing the dye can also exhibit the maximum absorbance in the range of 370 nm to 430 nm within the wavelength range of 380 nm to 780 nm. Since the above dye absorbs in the blue region, it is possible to exhibit a yellow tint. The dye may be a single dye or a mixture of two or more dyes within the range that the circularly polarizing plate exhibits the above transmittance characteristics.

Examples of the dyes include anthraquinone dyes, methine dyes, azomethine dyes, oxazine dyes, azo dyes, styryl dyes, coumarin dyes, porphyrin dyes, dibenzofuranone dyes, diketopyrrolopyrrole dyes, and rhodamine dyes. One or more dyes selected from the group consisting of dyes, xanthene-based dyes and pyrromethene-based dyes can be used.

The dye may be included in any layer included in the circularly polarizing plate within the range that allows the circularly polarizing plate to exhibit the above transmittance.

For example, the dye may be included in one or more of the antireflection film, retardation film, and adhesive layer. In one example, the dye can be included in the antireflective film. As described above, the antireflection film may include a substrate layer and a low refractive layer on one side of the substrate layer. In this case, the dye may be included in the base layer of the antireflective film. Alternatively, as described above, the antireflection film may further include a hard coating layer between the base layer and the low refractive layer. In this case, the dye may be included in the hard-coding layer of the antireflective film. In one example, the dye can be included in the retardation film. As described above, when the retardation film is a liquid crystal polymer film, the retardation film may include a substrate layer and a liquid crystal layer on one surface of the substrate layer. In this case, the dye may be included in the base layer of the retardation film. On the other hand, when the retardation film is a stretched polymer film, the dye may be contained in the stretched polymer film. In one example, the dye may be included in the adhesive layer.

In another example, the circularly polarizing plate may further include a separate layer for containing a dye, in addition to the antireflection film, the retardation film, and the adhesive layer. Such a separate layer may also contain the dye while containing the light-transmitting resin as a main component. The position of the separate layer is not particularly limited, and may be formed on one or both sides of the antireflection film, polarizer, retardation film, or adhesive layer. However, since the pressure-sensitive adhesive layer is used for adhering the circularly polarizing plate to the panel, it is preferably not present on the adhesion surface of the pressure-sensitive adhesive layer.

The dye-containing layer may have a transmission of 75% or less, 70% or less, 65% or less, or 60% or less at 430 nm wavelength. By satisfying such a transmittance range, the dye-containing layer can contribute to the neutral reflection color, so that even if a retardation film with flat dispersion characteristics is used, the reflective visual sensation can be improved. More specifically, the dye-containing layer may have a transmittance of 90% or more for 460 nm and 550 nm wavelengths, respectively. The lower limit of the transmittance of the dye-containing layer to a wavelength of 430 nm may be 10% or more. If the transmittance is too low, the color change of the white light emitted by the OLED becomes excessively large, so the lower limit of the transmittance of the dye-containing layer is preferably within the above range.

The dye content in the dye-containing layer can be appropriately selected in consideration of the purpose of the present application. As described above, the dye-containing layer may contain the light-transmissive resin as a main component and further contain the dye. The dye-containing layer may contain, for example, 0.5 to 10 parts by weight of the dye with respect to 100 parts by weight of the light-transmitting resin. When the dye content is within the above range, it may be suitable for improving the reflective visual sensation of the circularly polarizing plate. However, if the content of the dye is too high, the solubility of the dye may be insufficient and precipitation may occur, which may affect the physical properties of each layer.

If the dye weight is the same in the dye-containing layer, the same transmittance characteristics can be obtained by varying the thickness of the dye-containing layer. Therefore, when the transmittance of the dye-containing layer is to be increased within the range described above, the thickness of the dye-containing layer is fixed and the weight of the dye is reduced to lower the concentration of the dye. One method is to reduce the weight of the dye by reducing the thickness of the layer containing the same concentration of dye.

The present application also relates to a display device comprising said circular polarizer. An example of the display device is an OLED (Organic Light Emitting Diode) device.

FIG. 3 exemplarily shows an OLED device of the present application. As shown in FIG. 3, an OLED device can include an OLED panel 200 and a circular polarizer 100 disposed on one side of the OLED panel. The OLED panel and the circularly polarizing plate can be attached via the adhesive layer 40 .

The OLED panel may sequentially include a substrate, a bottom electrode, an organic light emitting layer and a top electrode. The organic light emitting layer may include an organic material capable of emitting light when a voltage is applied between the lower electrode and the upper electrode. One of the lower electrode and the upper electrode may be an anode, and the other one may be a cathode. The positive electrode is an electrode into which holes are injected and may be made of a conductive material with a high work function, and the negative electrode is an electrode into which electrons are injected and is made of a conductive material with a low work function. obtain. Generally, a transparent metal oxide layer such as ITO or IZO having a high work function can be used as a positive electrode, and a metal electrode having a low work function can be used as a negative electrode. Since the organic light-emitting layer is generally transparent, a transparent display can be realized when the upper and lower electrodes are transparent. In one example, if the thickness of the metal electrode is made very thin, a transparent display can be implemented.

The OLED panel may further include a sealing substrate that prevents moisture and/or oxygen from entering the upper electrode from the outside. Additional layers may be further included between the lower electrode and the organic light emitting layer and between the upper electrode and the organic light emitting layer. The additional layers include a hole transporting layer, a hole injecting layer, an electron injecting layer and an electron transporting layer for balancing electrons and holes. can include, but is not limited to,

The circularly polarizing plate may be arranged on the side from which light exits the OLED element. For example, in the case of a bottom emission structure in which light is emitted to the base substrate side, it may be arranged outside the base substrate, and in the case of a top emission structure in which light is emitted to the encapsulation substrate side, the encapsulation structure may be arranged. It can be arranged outside the stop substrate. The circular polarizer improves visibility and display performance by preventing external light from reflecting off the reflective layer made of metal, such as the electrodes and wiring of the OLED panel, from exiting the OLED panel. can be done.

In one example, the OLED panel may further include a substrate on which color filters are formed. The substrate on which the color filters are formed may be placed on the opposite side of the OLED panel on which the metal electrodes are placed. At this time, the OLED panel may have a structure including, in order, a substrate on which a color filter is formed, a transparent metal oxide electrode (positive electrode), a light emitting layer, a metal electrode (negative electrode), and a base substrate. The color filter may include Red, Green and Blue regions, and may further include a black matrix for dividing the regions. The presence of a color filter on the substrate of the OLED panel may exhibit lower reflectivity than the absence of the color filter. Specifically, when the red, green, and blue color filters are positioned in front of the light-emitting layer of the OLED, this is to reduce the high reflectance of the metal electrode positioned on the back surface of the light-emitting layer.

The average reflectance in the 410 nm-500 nm region of the OLED panel may be 45% or less. The average reflectance in the 410 nm-500 nm region of the OLED panel may be 20% or more. Also, the OLED panel has an average reflectance of 50% or less in the region of 600 nm to 650 nm. The OLED panel may have an average reflectance of 20% or more in the 600 nm-650 nm region. Through the application of such OLED panels, it may be further advantageous to use retardation films with flat dispersion properties to improve reflective visual perception.

As mentioned above, the OLED device applying the circularly polarizing plate of the present application to the OLED panel can exhibit excellent reflective visual sensation. In one example, the OLED panel to which the circularly polarizing plate is attached may have a reflectance of 1.5% or less, 1.4% or less, or 1.3% or less at 550 nm. Specifically, the reflectance may be 1.1% or less or 1.0% or less. The lower the reflectance of the OLED panel to which the circularly polarizing plate is attached, the better the reflective visual sensation. The lower limit is not particularly limited, but may be, for example, 0.1% or more.

In one example, the reflected color of the OLED panel to which the circularly polarizing plate is attached may have an a ^* value of less than 8 and ab ^* value of more than -8.5 based on L ^* a ^* b ^* color coordinates. The lower limit of a ^* may be greater than zero and the upper limit of b ^* may be less than zero. When the reflectance and the reflected color of the OLED panel with the circularly polarizing plate are within the above ranges, the reflective visual sensation is excellent. In addition, among the a ^* and b ^* values, the range of the a ^* value may be more important. This is because, in general, the reflective color perception of red light lowers the visual sensation of the observer more than that of blue light. be. In addition, when the reflectance of the OLED panel for a wavelength of 550 nm is within the above range, even if the absolute values of a ^* and b ^* are increased, the panel feels blacker, which may be more advantageous for improving the reflective visual sensation.

The present application can provide a circularly polarizing plate and an OLED device including the circularly polarizing plate that can improve the reflection color using a retardation film with flat dispersion characteristics.

The drawing which exemplarily showed the circularly-polarizing plate of this application. FIG. 2 is a drawing showing an exemplary reflectance spectrum of an antireflection film; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing exemplifying an OLED device of the present application; FIG. 4 is a drawing showing a transmittance spectrum of an adhesive layer containing a blue cut die; FIG. Drawing which showed the reflectance spectrum of an antireflection film. 9 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 3. FIG. 9 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 3. FIG. 9 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 3. FIG. 9 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 3. FIG. FIG. 10 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 4. FIG. FIG. 10 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 4. FIG. FIG. 10 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 4. FIG. FIG. 10 is a drawing showing evaluation results of reflex visual sensation in Evaluation Example 4. FIG. FIG. 10 is a diagram showing the results of measuring the transmittance of the circularly polarizing plates of Comparative Example 30 and Example 17. FIG.

Hereinafter, the present application will be specifically described through examples according to the present application and comparative examples not in accordance with the present application, but the scope of the present application is not limited by the examples presented below.

[Examples 1 to 12 and Comparative Examples 1 to 28]
(Circularly polarizing plate)
A circularly polarizing plate comprising an antireflection film, a polarizer, a retardation film and an adhesive layer in this order was prepared.

The antireflection film is formed by coating a triacetyl cellulose (TAC) base film with a hard coating layer having a thickness of about 5 μm, and then coating a low refractive layer containing hollow silica nanoparticles on the hard coating layer. Manufactured by The low refractive layer has a refractive index of about 1.3-1.4 for a wavelength of 550 nm. The antireflection film can adjust the minimum reflectance by controlling the refractive index of the low refractive layer. Specifically, the lower the refractive index of the low refractive layer, the lower the minimum reflectance at the minimum reflection wavelength of the antireflection film. The thickness of the low refractive layer is controlled within a range of about 70 nm to 150 nm, and the minimum reflection wavelength of the antireflection film can be adjusted by controlling the thickness of the low refractive layer. Specifically, the minimum reflection wavelength of the antireflection film shifts to a longer wavelength as the thickness of the low refractive layer increases, and shifts to a shorter wavelength as the thickness of the low refractive layer decreases. By adjusting the thickness within the above thickness range and changing the minimum reflection wavelength of the anti-reflection film, 8 kinds of anti-reflection films were prepared as shown in Table 1 below.

The retardation film is a product manufactured by Zeon by obliquely stretching a COP film, and has an R(450)/R(550) value of 1. The angle formed by the slow axis was 45 degrees, and samples were prepared by changing the in-plane retardation value for a wavelength of 550 nm as shown in Tables 1 to 5 below.

A PVA-based polarizer having a transmittance of 44% was used as the polarizer.

The pressure-sensitive adhesive layer is laminated on the retardation film using the product coated between the release films. The pressure-sensitive adhesive layer uses a commercially available acrylic pressure-sensitive adhesive for polarizing plates, and contains blue cut dye in the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer containing the blue cut dye has a transmittance of 43% for a wavelength of 430 nm and a transmittance of 90% or more for wavelengths of 460 nm and 550 nm, respectively. The blue cut dyes are two dyes with different maximum absorption wavelengths in the blue region available from Eutec Chemical Co. , Ltd. A mixture of Eusorb UV-390 and Eusorb UV-1990 from Co., Inc. was used.

(OLED panel)
The above circularly polarizing plate was attached to an OLED panel. The OLED panel used was manufactured by LGD, which has an average reflectance of 40% in the wavelength range of 410 nm to 550 nm and an average reflectance of 48% in the wavelength range of 600 nm to 650 nm.

[Evaluation example 1. Surface reflection property evaluation of antireflection film]
The surface reflection properties of the antireflection film were evaluated by measuring the reflection color and reflectance. Table 1 shows the minimum reflection wavelength, reflection color (L ^* a ^* b ^* color coordinates) and reflectance measurement results of the antireflection film.

The reflectance of the anti-reflection film is measured by attaching a black tape that absorbs light to the back of the anti-reflection coating layer on the base material, and then measuring the mirror reflectance of the surface layer of the anti-reflection coating layer using Minolta's CM-2600d equipment. was measured. Specifically, the reflectance is a value obtained by subtracting an SCE (Specular Component Excluded) value from an SCI (Specular Component Included) value among the measured values of the equipment. Simultaneously with the above measurements, CIE 1976 L ^* a ^* b ^* under D65 illuminant conditions can be obtained with the measurement equipment. Since most of the SCE value is the value reflected from the black tape attached to the back rather than the antireflection film, the SCE value was subtracted in order to accurately judge the reflection characteristics of the antireflection film.

Table 1 shows the L ^* a ^* b ^* color coordinates of the reflection color of the antireflection film, the luminous reflectance (Y), and the reflectance at 550 nm.

[Evaluation example 2. Evaluation of reflex visual sensation]
For the OLED panels to which the circularly polarizing plates of the above examples and comparative examples were attached, the reflective visual sensation was evaluated according to the configuration of the circularly polarizing plates. At this time, the OLED panel is in the electric field OFF state. Specifically, the L ^* a ^* b ^* color coordinates were measured for the OLED panel to which the circularly polarizing plate was attached. When the L ^* a ^* b ^* color coordinate standard a ^* is less than 8 and b ^* is greater than -8.5 under the D65 light source environment, it can be evaluated that the reflective visual sensation is excellent.

The retardation value and optical axis of the retardation film are determined using Axoscan equipment of Axometrics, and the transmittance and absorption axis of the polarizer are determined using V-7100 Spectrophotometer equipment of Jasco.

The transmittance of the adhesive layer containing the blue cut dye was measured using Shimadzu UV-3600. Specifically, after attaching an adhesive containing a blue cut die to a glass substrate, the measurement was performed using a sample in which a transparent PET film was further attached to the exposed adhesive surface. When setting the baseline of the equipment before measuring the sample, the sample was loaded with a transparent adhesive instead of the adhesive that had the same structure as the measurement sample and contained a blue cut die. As a result, the transmittance of the measured sample was measured under the condition that the reflectance was not included, and therefore the transmittance in the wavelength band without dye absorption is 100%.

The reflectance of the anti-reflection film is determined by attaching a black tape that absorbs light to the back of the anti-reflection coating layer of the substrate, and then measuring the mirror reflection of the surface layer of the anti-reflection coating layer using Minolta's CM-2600d equipment. rate was measured. Specifically, the reflectance is a value obtained by subtracting an SCE (Specular Component Excluded) value from an SCI (Specular Component Included) value among the measured values of the equipment. When measuring the reflectance, a difference was observed in the measured value depending on the direction of the absorption axis of the polarizer, and the measurement was performed under the condition that the length direction of the measuring machine and the direction of the absorption axis of the polarizer were horizontal. Haze is measured using Murakami Color Research Laboratory HM-150 equipment. L ^* a ^* b ^* color coordinates are determined by attaching a circularly polarizing plate to an OLED panel using Minolta's CM-2600d equipment and measuring the reflectance and reflected color according to the CIE 1964/10° standard under D65 light conditions. . The evaluation results of reflex visual sensation are shown in Tables 1 to 6 and FIGS. 6 to 9. In the table below, Y(D65) means luminous reflectance (%) and R@(550) means reflectance (%) at 550 nm. The transmittance of the circularly polarizing plate was measured using a Jasco V-7100 Spectrophotometer.

[Evaluation example 3. Evaluation of reflective visual sensation by combination of minimum reflection wavelength of antireflection film and phase difference of retardation film]
After attaching the circularly polarizing plate adjusted as shown in Tables 2 to 6 below to the OLED panel, the reflection color was evaluated by the above method, and the results were obtained. are shown in Tables 2 to 6 and FIGS. 6 to 9 below. The transmittance of the circularly polarizing plates of Examples 1 to 12 and Comparative Examples 1 to 28 in Tables 2 to 6 for light with a wavelength of 430 nm is about 17%.

FIG. 4 exemplarily shows a transmittance spectrum of an adhesive layer containing a blue cut dye having a transmittance of 43% for light with a wavelength of 430 nm.

FIG. 5 exemplarily shows reflectance spectra of antireflection films with minimum reflection wavelengths of 420 nm and 540 nm, respectively.

[Examples 13 to 20 and Comparative Examples 29 and 30]
Circularly polarizing plates were prepared in Examples 13 to 20 and Comparative Examples 29 and 30 by adjusting the transmittance of the pressure-sensitive adhesive layer containing the blue cut dye to a wavelength of 430 nm as shown in Table 7 below. In Examples 13 to 20 and Comparative Examples 29 and 30, the minimum reflection wavelength of the antireflection film is 430 nm, and the in-plane retardation value of the retardation film at a wavelength of 550 nm is 140.0 nm. The angle formed by the slow axis and the absorption axis of the polarizer is 45 degrees, and the configuration is the same as in Example 1 except for this. The above circularly polarizing plate was attached to an OLED panel. The OLED panel is the same as in Example 1. The transmittance of the adhesive layer decreases as the density of the blue cut dye increases. For example, an adhesive with a transmittance of 43% for a 430 nm wavelength is a sample added with 0.3 wt% of the blue cut dye Eusorb UV-390 and 4 wt% of Eusorb UV-1990 relative to the 20 μm thick adhesive, and the 430 nm wavelength is The adhesive with a transmittance of 10% is a sample made by increasing the thickness of the adhesive containing the same amount of dye as the adhesive with a transmittance of 43% by 2.7 times. The adhesive with a wavelength transmittance of 100% is a sample using a transparent adhesive that does not contain a blue cut dye dye compared to the adhesive with a transmittance of 43%.

FIG. 14 shows the results of measuring the transmittance of the circularly polarizing plates of Comparative Example 30 and Example 17. As shown in FIG. The above transmittance is the transmittance measured for the circular polarizer itself before attaching the circular polarizer to the OLED panel. FIGS. 14(a) and 14(b) express the same experimental results by changing only the wavelength range on the x-axis (a: 400 to 500 nm, b: 400 to 700 nm). Example 17 exhibits about 17.5% transmission for the 430 nm wavelength, and greater than 40% transmission for the 460 nm and 550 nm wavelengths. Comparative Example 30 exhibits a transmittance of about 41% for the 430 nm wavelength and a transmittance of 40% or more for the 460 nm and 550 nm wavelengths.

[Evaluation example 4. Evaluation of reflective visual sensation based on transmittance of pressure-sensitive adhesive layer]
The OLED panels to which the circularly polarizing plates of Examples 13 to 20 and Comparative Examples 29 and 30 were attached were evaluated for reflection color in the same manner as in Evaluation Example 1 above, and the results are shown in Table 7 below and FIGS. 13. In Table 7 below, Δxy means the difference between the x and y color coordinates of the white emission color of the OLED panel when the pressure-sensitive adhesive layer containing the blue cut dye is applied and not applied; The larger the value, the more intense the color change of the emitted light when driving the OLED panel.

10: Antireflection film 20: Polarizer 30: Retardation film 40: Adhesive layer

Claims (13)

An antireflection film, a polarizer, a retardation film having an R (450) / R (550) value of 0.99 to 1.01, and a circularly polarizing plate comprising an adhesive layer in this order, The minimum reflection wavelength is 470 nm or less, the in-plane retardation value of the retardation film at a wavelength of 550 nm is 136.0 nm or more, the transmittance of the circularly polarizing plate at a wavelength of 430 nm is 30% or less, and the The antireflection film has one wavelength band in which the reflectance is 1% or less in the wavelength range of 380 nm to 780 nm, and the pressure-sensitive adhesive layer contains a dye that exhibits the maximum absorbance in the wavelength range of 370 nm to 430 nm. , wherein the circularly polarizing plate has a transmittance of 40% or more for wavelengths of 460 nm and 550 nm (R(λ) is an in-plane retardation value for a wavelength of λ nm). 2. The circularly polarizing plate according to claim 1, wherein said antireflection film has a minimum reflection wavelength of 390 nm or more. 3. The circularly polarizing plate according to claim 1, wherein the antireflection film has a haze of 1% or less. 4. The antireflection film according to any one of claims 1 to 3, wherein the reflection color satisfies a ^* >0, b ^* >0 and a ^* <b ^* in terms of L ^* a ^* b ^* color coordinates. circular polarizer. 5. The circularly polarizing plate according to claim 1, wherein the polarizer has a transmittance of 40% to 50% for a wavelength of 550 nm. 6. The circularly polarizing plate according to claim 1, wherein the retardation film has an in-plane retardation value of 143 nm or less at a wavelength of 550 nm. The circularly polarizing plate according to any one of claims 1 to 6, wherein the slow axis of the retardation film forms 43 to 47 degrees with the absorption axis of the polarizer. The circularly polarizing plate according to any one of claims 1 to 7, wherein the retardation film is a liquid crystal polymerized film or a stretched polymer film. The circularly polarizing plate according to any one of claims 1 to 8 , wherein the circularly polarizing plate has a transmittance of 4% or more for a wavelength of 430 nm. An OLED device comprising an OLED panel and a circularly polarizing plate according to any one of claims 1 to 9 arranged on one side of the OLED panel. 11. The OLED device according to claim 10 , wherein the OLED panel has an average reflectance of no more than 45% for wavelengths in the range of 410 nm to 500 nm, and an average reflectance of no more than 50% for wavelengths in the range of 600 nm to 650 nm. 12. The OLED device according to claim 10 or 11 , wherein the OLED panel to which the circularly polarizing plate is attached has a reflectance of 1.3% or less for a wavelength of 550 nm. 13. The reflected color of the OLED panel to which the circularly polarizing plate is attached satisfies a ^* <8 and b ^* >- 8.5 in terms of L ^* a ^* b ^* color coordinates. OLED device according to .

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